OEM 2003 Toyota 4Runner Cylinder Head Gasket

2003 Toyota 4Runner Parts Questions & Experts Answers

• Q: How to replace the Cylinder Head Gasket on 2003 Toyota 4Runner?

  A: The first step to install the Cylinder Head Gasket involves preventing gasoline spills and then removing the chain sub-assembly followed by taking out cool air inlet No.1 bolts and air cleaner hoses and finally removing the transmission oil filler tube sub-assembly by removing the ATF level gauge a bolt and the O-ring. First disconnect the A/F sensor connector and remove 6 nuts to detach the exhaust manifold sub-assembly RH from the exhaust line. Then remove the exhaust pipe assembly front and manifold stay by taking out 3 bolts. The intake manifold must be taken out by disconnecting 6 fuel injector connectors followed by the removal of 10 bolts and 2 gaskets and 6 fuel pipe sub-assemblies No.1 and No.2. To remove the water by-pass joint RR you must first disconnect the engine coolant temperature sensor connector and heater hose while separating 2 bolts and 4 nuts before extracting the water by-pass joint RR together with its 2 gaskets while removing the O-ring from the water outlet pipe. After raising chain tensioner No. 2 and inserting a 1.0 mm pin to keep it stable you must use a wrench to hold the hexagonal camshaft portion while removing 2 bolts and collecting the camshaft timing gear assembly with timing chain No. 2 along with the camshaft timing gear. Take care not to damage the valve lifter and cylinder head. Proper removal procedure requires no.2 chain tensioner assembly followed by cautious removal of the camshafts with maintenance of level orientation to prevent damage. The entire operation requires loose removal of 16 bearing cap bolts in specified order in addition to extraction of 8 bearing caps and 2 camshafts. Perform removal of camshaft bearing No.2 together with the cylinder head sub-assembly by disconnecting two ground cables alongside uniform loosening of eight cylinder head bolts with a 10 mm bi-hexagon wrench and then lift the cylinder head from the dowels on the cylinder block to wooden blocks placement. A vernier caliper measurement of the cylinder head set bolt outside diameter must be performed to check if the measurements fall within standard specifications while working with the removed cylinder head gasket. Cleaning old packing material followed by applying continuous bead of seal packing (Part No. 08826-00080 or equivalent) allows the installation of a new cylinder head gasket with the Lot No. stamp facing upward on the cylinder block surface. The cylinder head sub-assembly installation procedure involves placing the gasket underneath followed by applying engine oil to the cylinder head bolt threads then tightening all bolts equally to 36 Nm before marking the leading bolt side then refitting at 180° as per specifications. Fit bearing No.2 before installing camshafts in a leveled position using fresh engine oil and torquing 16 bearing cap bolts according to the specified values. Position chain tensioner assembly No.2 while aligning marks present on the camshaft timing gears with timing marks then tighten bolts up to 100 Nm. Install the water by-pass joint RR using new O-rings and gaskets and then connect the heater hose along with engine coolant temperature sensor connector. The intake manifold should get installed with new gaskets while tightening bolts to 28 Nm. The procedure includes connecting fuel pipe sub-assemblies No.1 and No.2 followed by exhaust manifold sub-assembly RH installation with a new gasket and a 30 Nm torque on the nuts. This work ends with A/F sensor connector attachment. Install the manifold stay with 3 bolts to 40 Nm and the exhaust pipe assembly front and transmission oil filler tube sub-assembly with a new O-ring which should be tightened to 12 Nm. The last step involves installing the cool air inlet No.1 followed by leak checks for fuel and exhaust gas and use of Special Service Tool: 09843-18030 for idle speed inspection and CO/HC level examination.